Hester et al U.S. Pat. No. 6,904,626, assigned to the assignee of the present application, discloses a spa tub nozzle having a fluidic oscillator comprised of a power nozzle in the fluidic oscillator that is coupled to a source of water under pressure. The power nozzle projects a jet of water into an interaction region having top, bottom and diverging sidewalls and an inertance loop connecting the control ports to each other. The inertance loop coupling the control ports to each other is comprised of a pair of flat plates with inertance grooves formed therein and having one end juxtaposed over an aperture in sidewalls of the respective control port and a passthrough passage connecting the opposite ends of the grooves to each other. The passthrough passage has a water ingestion port for purging air from the inertance loop.
The present invention incorporates a housing similar to the housing in the above-identified Hester patent. The operative fluidic oscillator component comprises a molded inlet piece having a power nozzle and a very compact inertance loop wound around the control ports in a spiral-like configuration which is in a plane that is transverse to the centerline or longitudinal axis of the fluidic oscillator. The seal plate for the inertance loop is preferably part of a molded outlet piece having portions of the interaction region constituted by a pair of diverging sidewalls, top and bottom walls, and an outlet flange. A jet face member locks the components in position in the housing. A small O-ring fits in a groove on the outer surface of the inlet piece separating the water inlet from an air chamber. A large O-ring fitted in the inlet piece portion constituted by the spiral-like inertance loop provides the air chamber for the entrainment air inlet. The air inlet is coupled through the space occupied by the inertance loop to an elbow which steers the air to an air entrainment orifice in the outlet piece.
Thus, the invention features a compact fluidic spa nozzle, constituted by an inertance loop traversing a continuous path in a plane that it is transverse to the centerline of the fluidic oscillator. The path for feeding entrainment air is through a path that is transverse to the inertance loop. The mold lines for the upstream or inlet piece and the downstream or outlet piece is through the plane of the inertance loop. Control ports are partly formed by both halves of the molding, namely, the upstream inlet piece and the outlet downstream piece. Thus, the invention features a reduced number of parts in its construction assembly. A flow straightener/conditioner is provided on the inlet piece.
Reference is made to the following U.S. patents owned by the assignee hereof and incorporated herein by reference:                U.S. Pat. No. 6,729,564        U.S. Pat. No. 6,904,626        U.S. Pat. No. 6,948,244        U.S. Pat. No. 6,575,386        Des. 450,804        